Hydrochloric Acid → 1,3-Dihydroisobenzofuran

Participants

Reaction Steps

Lithium aluminum hydride (0.2 g) was added to approximately 40 ml of dry tetrahydrofuran at room temperature under nitrogen. 3-[4'-(dimethyl)amino-1'-phenyl)-3-(3",5"-diisopropyl-4"-oxo-1"-phenyl)phthalide (1.0 g) was dissolved in 40 ml dry tetrahydrofuran and the solution added dropwise to the lithium aluminum hydride suspension. The temperaturerose to about 30° C. Upon completion of addition, a sample of the reaction mixture was poured into water and extracted with ether. TLC on silica gel with 1:1 ether/petroleum ether showed completion of the reaction and no unreacted phthalide. After neutralizing the lithium aluminum hydride with ethylacetate, the reaction mixture was poured into 200 ml water, the pH adjusted to 3 with HCl and extracted with ether. The ether layer was washed with 200 ml of 5% aqueous sodium hydroxide, dried over sodium sulfate and the ether evaporated to leave a pink-red residue. The residue was dissolved in about 20 ml ether, and petroleum ether was added to precipitate a white solid. The solution after filtering was evaporated to give the corresponding phthalan as a pink solid.

Provenance & Evidence